Research Interests

Research Summary

Dr. Brown studies memory difficulties with neurological disorders. He is studying different cognitive tests to determine which seem to best differentiate Alzheimer's related cognitive decline from non-Alzheimer's causes such as the chronic effects of medical difficulties (cardiovascular disease, obesity, diabetes, etc.). This is important in that a patient with a medically caused form of cognitive impairment may be able to reduce decline through better control of their conditions, whereas Alzheimer’s Disease may require other forms of intervention or have different expectations for patients. Though biomarkers are also being studied, cognitive markers are also important for identifying actual symptoms of the disorder, and the need for treatment.

Though he has a general interest in cognition, Dr. Brown is most known for the development of the Brown Location Test which is a test of visual memory that does not require drawing skills, is not verbally encodable, and lacks a clear pattern, unlike many of the well-established visual memory tests. This has demonstrated validity in Temporal Lobe Epilepsy Patients, and is currently being studied in a variety of other patient populations.

He is also further exploring measures of cognitive efficiency. The inability to think efficiently may help explain why some individuals with cognitive complaints from the real world may do well on some test batteries; even though objective third party observers have noticed their difficulties. Many neuropsychological tests may have difficulty measuring thinking efficiency because they are designed to measure one key function; whereas thinking efficiency requires multiple functions working together. This tends to rely on connectivity between areas of the brain, which is heavily reliant on white matter pathways. Thus, cognitive efficiency is an important area to study in disorders with white matter abnormalities (e.g., Multiple Sclerosis).

Extensive Research Description

Specific ongoing research includes the following. Visual memory functioning in pre and postsurgical temporal lobe epilepsy patients. I am administering complete epilepsy batteries including the Brown Location Test to epilepsy patients before or after surgery with the goal of identifying those more consistently associated with right temporal lobe epilepsy, and the utility in predicting postsurgical changes. Within this general area, I am also studying the effects of medication, anxiety, depression and other non-neurological variables upon cognitive test performance in presurgical evaluations. Furthermore, we have been finding an interesting association between math and visual memory which is further being explored within epilepsy and other patient populations.

Within multiple sclerosis, I am studying which cognitive tests are most sensitive to the effects of this disease. In addition to traditional MS related tests, I have added the Brown Location Test and Test of Variables of Attention to further study the effects of cognitive inefficiency within MS. Though MS is not typically a primary memory disorder, the BLT includes one subtest of delayed rotated memory which was designed to assess allocentric memory. In preliminary analysis this appears more sensitive to MS than more traditional measures. We are exploring whether this isolated weakness could be related to reduced connectivity due to the effects of MS. My overreaching goal is to identify measures most sensitive to changes with MS and have these ultitmately included as a key measure of disease progression.

Alzheimer's disease is often quoted as the most common cause of dementia. However, in my clinical referrals this does not seem to be the case even though many of those referred have been preliminarily thought to have AD. Yet, on neuropsychological tests their profile seems more consistent with the effects of vascular disease and a subcortical profile - at least those who have mild cognitive impairment. My goal is to improve the accuracy of diagnoses and eventually determining which methods are most accurate according to postmortem studies.

In addition to the above discussed primary areas, I am always interested in new findings among clinically referred patients. Subcortical strokes is a particular area of interest in that they may produce minimal obvious physical changes, yet can impact cognition in ways that may not be immediately apparent but could dramatically impact quality of life and the ability to maintain employment. I have a small subset of thalamic stroke patients and would like to increase this data set to improve our understanding about how these impact cognition, and quality of life.